1. Field of the Invention
The present invention relates to a projection system, an image processing apparatus, and a computer-readable storage medium.
2. Description of the Related Art
In recent years, a multi-projection technique of arranging projection images from multiple projectors with overlapping areas intervening among the images and projecting a single high-resolution image onto a screen has received an attention.
As for the multi-projection technique explained above, Japanese Patent No. 3908255 has been known, for example. In an information projection system in Japanese Patent No. 3908255, a reference image including at least four feature points whose respective coordinate positions are known in advance is projected onto a screen by each projector in calibration. Here, the reference image is, for example, a known image with a grid pattern in which bright spots or cross shapes are aligned at regular intervals. Respective positions of the feature points in the reference image captured by a digital camera are detected, a projection image for each projector is deformed based on the detected positions of the at least four feature points of each projector, an overlapping area is detected, and a blending processing is performed. It is possible, by projecting the images after the deformation and the blending processing from the multiple projectors while aligning the images on the screen with overlapping areas intervening with each other, to project a single high-resolution image.
In a case of a usage as a permanent signage, positional displacement of a projector is inevitable with the passage of time due to a vibration even after the projector is once installed and adjusted in position and a slight displacement causes a significant deterioration in quality of the image. Therefore, it is necessary that a person in charge frequently goes to an actual place where the projector is installed permanently and checks the presence of a displacement, a technical expert having a maintenance skill is called when a displacement is recognized, and a calibration processing is performed by preparing a camera and a tripod again in the projection system in the conventional technique, which is cumbersome.
Under this background, demanded has been a development of a technique that enables an easy recalibration of a minute misalignment, attributed to a positional displacement with the passage of time, in a connection part of projection images in recalibration after an initial calibration without time and effort for the setting of a camera and a tripod and a manual fine adjustment again.